The primer blew the bullet into the forcing cone and tied up the gun. A few whacks with the RO's range rod and hammer jammed the bullet back into the case and I was able to clear the gun then put it away. Guy then showed me a pic of a S&W 1917 that blew up this past Thursday. A bullet stuck in the barrel and the next round split open the barrel about 2" from the muzzle. Unfortunately a shooter next to the 1917 caught a bit of shrapnel in his upper left arm and lost a little blood.
I hope that the firearms "trainers" who use KHSC brief their students about the possibility of squib rounds and the danger they present--it's bad enough to have to put up with newbie gun handling.
If I see Guy again next week I'll try to remember to get a copy of that picture to post here.